Then-mayor Bloomberg gives a commencement speech at Fordham in 2009. The University is suffering from a mumps outbreak, with 13 cases on its two campuses, the university said Thursday. Photo: Angel Chevresst

Fordham University is suffering from an outbreak of mumps, with 13 suspected cases reported on two campuses.

Early Thursday the university said that it had 10 cases since January, with nine of the them reported in the last three days.

Hours later the number had grown to 13, including new cases on the Rose Hill campus in The Bronx and on the Lincoln Center campus in Manhattan.

“All the students with suspected mumps infections have either returned home or have been isolated from other residents during the infectious phase of the illness,” Fordham officials said. “Typically mumps patients are contagious for two days prior to the outbreak of symptoms and five days after.”

Students said they were surprised to learn of the extent of outbreak.

“The school sent every single student an e-mail this morning telling us,” said freshman Johnathan Agostino, 20. “So now everybody is going around being a little extra careful.”

The highly contagious disease has spread at Fordham despite precautions.

“The thing is, just to get into Fordham you need to be vaccinated for mumps. So nobody knows if those kids got a bad vaccine or what,” Agostino said. “I just know I’m going straight to the health center if I see any symptoms.”

Fordham noted that the widely available mumps vaccinations do not guarantee 100 percent immunity.

“All of the students who were tentatively diagnosed with mumps had been vaccinated,” the university said in a statement. “Vaccinations do not offer 100 percent protection.”

Mumps can cause fever, headaches, muscle aches, swollen glands, fatigue and loss of appetite. Symptoms typically arise 16 to 18 days after infection, according to the US Centers for Disease Control and Prevention.

No lab tests have confirmed the disease at Fordham is mumps, but the university said “that is the most likely diagnosis.”

“Mumps in college-age men and women usually runs its course without any lasting effects,” the university said. “Nonetheless, the university is trying to see what connection there might be among the affected students while stepping up the frequency and intensity of cleanings in communal bathrooms.”